The present invention relates to a canted washer or spring; and more particularly a washer or spring retaining a coupling ring in locking engagement for non-self locking electrical connectors.
The wave spring is commonly used within an electrical connector, particularly between the connector coupling ring and the mated plug and receptacle subassemblies. The wave spring has a spring deflection response which is variable dependent upon the manufacturing tolerances of that spring and the amount of compression to which it is subjected within the electrical connector.
A wave spring traditionally used in the fabrication of electrical connectors is operable to be fabricated inexpensively. However, its inability to maintain deflection and its inability to be manufactured to specific tension requirements limits its use.
A non-bayonet electrical connector consists of a plug, a receptacle and a coupling ring. The plug and receptacle matingly engage within the coupling ring. The coupling ring has interior threads which engage the exterior threads of the receptacle. After the plug and receptacle matingly engage the coupling ring is turned pulling the plug and receptacle tightly together. The mated plug and receptacle bottom out when their engaging surfaces meet. The plug has ratchet teeth and a plug shoulder between the engaged plug receptacle. A dimpled clutch plate surrounding the plug engages the teeth of the plug locking the coupling ring in place.
Friction washers or wave springs are also used in conjunction with the clutch plate to facilitate locking engagement of the coupling ring around the plug and receptacle. A non-bayonet electrical connector incorporating the traditional friction washer or wave spring is locked using tools or the human hand. Force applied to tighten the coupling ring to lock down the ratcheted plug within the coupling ring to the last rachet tooth ensures that there is no looseness or "play" between the mated subassemblies and the coupling ring. When the mated electrical connector is exposed to high vibrational forces, any play between the engaged plug and receptacle and the coupling ring results in a loosening of the coupling ring.
Specifically, hand tightening of the coupling ring does not secure the coupling ring around the mated subassemblies to the last available ratchet. The human hand cannot apply sufficient force to tighten the coupling ring. Invariably, the rachet teeth of the plug fall between the dimples on the clutch plate. This failure to secure the coupling ring to the final ratchet results in the decoupling of the mated connector when it is subjected to high vibrational environments.
It is known, that a Belleville spring consists of an apertured disc made of spring metal and having a generally frustoconical shape. When force is applied to the Belleville spring in an axial direction, the spring deflects and initially exerts a relatively high resistive force which increases rapidly as a non-linear function of the deflection of the spring.
With continued deflection of the Belleville spring, the resistive force exerted by the spring decreases gradually as a substantially linear function of deflection until the spring toggles and once again exerts a force which increases non-linearly with deflection. With many applications, only the linear force/deflection characteristics of the spring are usable.
Washers and wave springs, having non-uniform surfaces, have been fabricated.
U.S. Pat. No. 2,431,120 issued to E. E. Howe Nov. 18, 1947 entitled "Joint for Tubing" discloses a cone shaped thrust plate held in place by a series of springs where the springs employ a corrugated washer. This corrugated spring washer, while split, is circular in configuration and comprises a multiplicity of random dimples or individual waves within the surface of the corrugated washer. The washer in this application is used in high pressure joints for tubing or pipes having thin walls providing a flexible connection for tubing including an elastic compressible sealing cushion member.
U.S. Pat. No. 4,711,434 issued to D. L. Haag Dec. 8, 1987 entitled "Spring Disk", discloses a solid spring disk made of a resiliently yieldable material shaped into a shallow cone having a corrugated surface defined by a plurality of angularly spaced triangular segments of identical size and shape disposed together upon the surface of the cone in a side-by-side arrangement.
The solid spring disk of the Haag device provides an improved spring disk which when compared with springs of the same linear force of deflection are smaller in size and require less material for fabrication. The Haag patented spring is a solid spring and is not a washer.
U.S. Pat. No. 3,748,888 issued to A. J. Gerich Jul. 31, 1973 entitled "Bi-metallic Snap Disk and Method and Apparatus for Making Same" discloses a snap disk having peripherally spaced radially extending scallops which stiffen the disk independent of the cord height of the disk.
The bi-metallic snap disk of the Gerich patent has two positions of mechanical stability. When the temperature of the snap disk is below a predetermined temperature which has been determined during the manufacturing stage, the disk exhibits one position of stability. When the temperature of the disk is raised to a second predetermined temperature or greater, the disk snaps into a second predetermined position of stability and remains in that second position of stability until the temperature of the disk is subjected to drops below the second predetermined temperature. The inventive concept of the Gerich snap disk does not describe a washer format.
U.S. Pat. No. 4,668,106 issued to A. L. Gu on May 26, 1987, entitled "Thrust Bearing Underspring", discloses a foil thrust bearing underspring having alternate upper ridges and lower ridges wherein the upper ridges have a height greater than the lower ridges. The Gu device is fabricated using strict tolerances thereby producing a device having a predetermined spring capability. This resiliency o spring rate of the underspring is varied by changing the thickness of the upper and lower ridges. The space that occurs between the adjacent lower ridges has a marked effect on the stiffness of the spring. The stiffness of the spring generally outwardly converges in order to better accommodate hydrodynamic pressure forces which increase radially upon the spring.